I have the exact same question and it that alright to put on my stock auto m3? As for gettin the aircharger instead of just the replacment filter, i would go with the aircharger, more acceleration and sounds sweet when layin on the gas. Also remember that the that K@N aircharger is illegal for on road use, doesnt really matter unless u live in a state where they inspect ur car. Anyway please help with my problem someone

I wouldnt waste your money on "air charger" kits. Trust me I have looked into them and read all about them, mostly they are good for looks and saving space. Get the regular filter, and search around for the "fogging you airbox" mod. This repositions the intake hose to behind your foglight. Way cheaper and probably works better.